An electrical machine, for example a generator, comprises a stator with a stator winding. The stator winding is conventionally formed by winding conductors, wherein the winding conductor is formed into an air-permeable winding braid. The stator is cylindrical, wherein the stator winding comprises a winding head at the end face. During operation of the generator, ohmic losses are produced in the stator winding and are conventionally dissipated from the generator by means of a cooling device. In particular, there is a risk due to the ohmic losses of overheating in the region of the end crown connection of the winding head, whereby high demands are placed on the cooling device for cooling the winding head in the region of the end crown connection.
As a cooling device, an air cooler is known that comprises an axial fan by means of which cooling air is conveyed axially into the housing in order to cool the stator winding. The cooling air flows through the winding braid, whereby heat is dissipated from the winding braid due to convection effects. In this case, it is problematic however that a hotspot of the winding braid may develop, in particular in the region of the end crown connection, whereby there is a risk of thermal overload of the winding braid in the region of the end crown connection.